The invention relates to a device and a method for increasing the sweep range of the antenna beam of the receiving array of imaging radar sensors.
Millimeter wave radar sensors, e.g. for automotive applications with short distances, should also have, in addition to high distance and angular resolution, the widest possible angle detection range so that the number of sensors fitted around the vehicle can be reduced to a minimum.
The sensors are generally used for the “active safety” application and, in addition to pedestrian protection, also serve to support the driver in town traffic and in dense stop-start traffic.
The dissertation by Dr. Winfried Mayer entitled “Imaging radar sensor with antenna array connected on the transmitting side”, Cuvillier Verlag, Goettingen 2008, ISBN 978-3-86727-565-1 discloses a method and a device which monitors an area with digital beam forming technology in which an antenna array with a number of transmitters and a number of receivers is used.
By means of the chronologically consecutive use of the transmitters the antenna opening angle can be reduced without the physical size of the receiving antenna thereby increasing.
In publication /1/ “N. Kees. E. Schmidhammer and J. Detlefsen “Improvement of angular resolution of a millimeterwave imaging system by transmitter location multiplexing” in IEEE MTT-S Int. Microw. Symp. Dig., Orlando, Fla. May 1995, vol. 2, pages 969-972” a method for producing a synthetic antenna aperture is described, with the aid of which the antenna beam width is reduced and so the angular resolution can be improved.